[INFO] fetching crate futures-async-stream 0.1.0-alpha.7...
[INFO] checking futures-async-stream-0.1.0-alpha.7 against try#5e633973aa9255a88b65a39484627bb54e6044b3 for pr-66063
[INFO] extracting crate futures-async-stream 0.1.0-alpha.7 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate futures-async-stream 0.1.0-alpha.7 on toolchain 5e633973aa9255a88b65a39484627bb54e6044b3
[INFO] running `"/workspace/cargo-home/bin/cargo" "+5e633973aa9255a88b65a39484627bb54e6044b3" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate futures-async-stream 0.1.0-alpha.7
[INFO] finished tweaking crates.io crate futures-async-stream 0.1.0-alpha.7
[INFO] tweaked toml for crates.io crate futures-async-stream 0.1.0-alpha.7 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate crates.io crate futures-async-stream 0.1.0-alpha.7 already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+5e633973aa9255a88b65a39484627bb54e6044b3" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=allow" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+5e633973aa9255a88b65a39484627bb54e6044b3" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 67b857da79fde17b6514006ce6f8878bfcb34c738eb3d3e00f2d8154818e5e3f
[INFO] running `"docker" "start" "-a" "67b857da79fde17b6514006ce6f8878bfcb34c738eb3d3e00f2d8154818e5e3f"`
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]     Checking futures-core-preview v0.3.0-alpha.18
[INFO] [stderr]    Compiling pin-project-internal v0.4.0
[INFO] [stderr]    Compiling compiletest_rs v0.3.22
[INFO] [stderr]     Checking async-ready v3.0.0
[INFO] [stderr]     Checking async-datagram v3.0.0
[INFO] [stderr]     Checking getrandom v0.1.12
[INFO] [stderr]     Checking tester v0.5.0
[INFO] [stderr]     Checking filetime v0.2.7
[INFO] [stderr]     Checking backtrace v0.3.37
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking futures-sink-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking failure v0.1.5
[INFO] [stderr]     Checking futures-channel-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking rand_chacha v0.2.1
[INFO] [stderr]     Checking rand v0.7.2
[INFO] [stderr]     Checking futures-util-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking tempfile v3.1.0
[INFO] [stderr]     Checking futures-executor-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking futures-preview v0.3.0-alpha.18
[INFO] [stderr]     Checking romio v0.3.0-alpha.10
[INFO] [stderr]    Compiling serde_derive v1.0.101
[INFO] [stderr]    Compiling futures-async-stream-macro v0.1.0-alpha.7
[INFO] [stderr]     Checking pin-project v0.4.0
[INFO] [stderr]     Checking futures-async-stream v0.1.0-alpha.7 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]    --> src/lib.rs:217:1
[INFO] [stderr]     |
[INFO] [stderr] 217 | #![feature(gen_future, generator_trait)]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `futures-async-stream`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "67b857da79fde17b6514006ce6f8878bfcb34c738eb3d3e00f2d8154818e5e3f"`
[INFO] running `"docker" "rm" "-f" "67b857da79fde17b6514006ce6f8878bfcb34c738eb3d3e00f2d8154818e5e3f"`
[INFO] [stdout] 67b857da79fde17b6514006ce6f8878bfcb34c738eb3d3e00f2d8154818e5e3f